Do you need whole-home battery backup in 2025?

Power outages don't have to mean scrambling for candles or worrying about spoiled food. With the right backup power solution, you can maintain your normal routines even when the grid goes down. Battery backup systems offer a clean, quiet alternative to noisy generators, providing reliable power when you need it most.

While many homeowners opt for partial backup systems that power essential appliances, whole-home battery backup takes energy independence to the next level. These robust systems can keep your entire house running during extended outages, from your HVAC system to your home office setup.

We'll cover what you need to know about whole-home battery backup—what it is, whether it's right for your home, and which systems offer the best performance and value in 2025.

Whole-home battery backup systems store enough electricity to power your entire house during an outage, maintaining normal energy consumption levels without any lifestyle changes. Unlike partial backup systems that only support essential loads like refrigerators, lights, and internet, whole-home setups keep every outlet, appliance, and system in your home operational.

The key difference lies in capacity and power output. Whole-home systems typically require 30 kilowatt-hours (kWh) or more of battery storage capacity—roughly equivalent to an average home's daily electricity consumption. A system this large comes with a higher price tag, often costing three times more than partial backup systems.

*Prices are based on the average cost of a battery ($1,151/kWh) and reflect the federal tax credit—which is expiring for systems installed after December 31, 2025—but don't include solar panels, which you'll need to keep your battery charged during an outage.

The batteries used in both systems are identical—whole-home backup simply requires more of them. Think of it like generators: You can choose a small portable unit for essential needs or a standby generator for your entire house. The difference is that battery backup systems rely on clean, stored electricity rather than expensive fuel.

Do you need whole-home or partial-home battery backup?

For most American homes, partial battery backup systems make more sense financially and practically. Extended power outages are relatively infrequent in most parts of the country, making the extra investment in whole-home capacity unnecessary for typical use cases.

However, whole-home battery backup may be worth considering if you:

• Live in an area with frequent or prolonged outages

• Work from home and need uninterrupted power for equipment

• Have medical devices that require consistent electricity

• Want complete energy independence during grid disruptions

• Have a large home with high electricity consumption

The decision often depends on your risk tolerance, budget, and how much inconvenience you're willing to accept during outages.

1. HomeGrid Stack'd Series: Most powerful and scalable

• Price: $862/kWh

• Roundtrip efficiency: 98%

• What capacity you should get: 33.6 kWh

• How many you need: 1

The HomeGrid Stack'd series tops our list with the biggest capacity and most scalable design available. A single stack provides up to 38.4 kWh of usable capacity, with the potential to scale up to 576 kWh total—making it more than capable of handling whole-home backup needs.

With continuous power up to 14.4 kW, the Stack'd Series can run multiple high-demand appliances simultaneously. Its modular design allows you to add capacity as your needs grow, and it boasts our highest efficiency rating at 98%, meaning you get more usable power from every charge.

The main drawback is HomeGrid's warranty, which only guarantees 60% of initial capacity at the end of its term, compared to the 70% guarantee offered by most competitors.

2. Duracell Power Center Max Hybrid: Best price

• Price: $813/kWh

• Roundtrip efficiency: 96%

• What capacity you should get: 30 kWh

• How many you need: 1

The Duracell Power Center Max Hybrid delivers substantial storage capacity with the highest continuous power output in its class—crucial for whole-home setups. It performs excellently across all metrics while maintaining an attractive price point, making it one of the most cost-effective options for comprehensive backup power. The 96% efficiency rating ensures minimal energy loss during storage and discharge.

However, Duracell's warranty falls short of competitors, offering only 10 years of coverage with a 70% capacity guarantee, while many others provide 12-15 years of protection.

3. Savant Power Storage: Best for whole-home integration

• Price: $846/kWh

• Roundtrip efficiency: 93.8%

• What capacity you should get: 37 kWh

• How many you need: 2

The Savant Power Storage system rounds out our top three with excellent integration capabilities for smart homes. With most homes requiring around 30 kWh for full-day backup, we recommend two of these 18.5 kWh units to meet your needs. The system can scale up to 180 kWh if you need even more capacity.

What sets Savant apart is its integration with home automation systems, allowing you to monitor and control energy usage directly from your smartphone. The 10-year warranty guaranteeing 75% of original capacity is slightly better than the industry standard of 70%.

The 12.5 kW continuous power output and 93.8% efficiency don't quite match the top performers from Duracell and HomeGrid, but they're still sufficient for most whole-home backup needs.

4. FranklinWH aPower 2: Longest warranty

• Price: $1,220/kWh

• Roundtrip efficiency: 90%

• What capacity you should get: 30 kWh

• How many you need: 2

FranklinWH earned its spot in our top five best solar batteries of 2025, and it's equally impressive for whole-home backup applications.

The aPower 2's standout feature is its industry-leading 15-year warranty—significantly longer than most competitors. With 13.6 kWh of usable capacity per unit, you'll need two batteries for adequate whole-home backup. The continuous power output is the lowest on our list at 10 kW, which reflects its AC-coupled design limitations.

While more expensive than other options, the extended warranty coverage provides valuable long-term peace of mind for this significant investment.

5. SolaX Power T-BAT H

• Price: $1,133/kWh

• Roundtrip efficiency: 95%

• What capacity you should get: 36 kWh

• How many you need: 2

The T-BAT H is also in our top-five best battery list thanks to its well-rounded performance and solid 12-year warranty. 

Each battery provides 18 kWh of usable capacity, scalable up to 72 kWh per inverter. While not the most powerful or scalable option, its 11.1 kW continuous and peak power output ensures reliable performance, and the 95% roundtrip efficiency maximizes your stored energy.

The AC or DC-coupled design makes it an excellent choice for adding storage to existing solar panel systems or maximizing efficiency in new systems. Despite its smaller individual capacity, its efficiency, scalability, and outstanding warranty make it a solid long-term investment.

*Price per kWh reflects the average battery cost from that brand, not the individual model.

**Total system price reflects the federal tax credit—which is ending for systems installed after December 31, 2025—but doesn't include solar panels.

When evaluating different battery systems for whole-home backup, several key factors determine which option best fits your needs and budget.

Battery backup systems provide crucial protection against power disruptions, but pairing them with solar panels creates true energy independence. This combination, known as solar-plus-storage, offers renewable resiliency that keeps your home powered even during extended grid outages.

Without battery backup, grid-connected solar systems shut down during outages for safety reasons—even if your panels generate enough electricity to power your entire home. Adding battery storage allows you to harness your solar production during outages while maintaining backup power for nighttime or cloudy conditions.